Gas burner and combustion control apparatus



GAS BURER AND COMBUSTION CONTROL APPARATUS Filed July 20, 1955 2 Sheets-Sheet-1 '/f 4001 ma man@ v mi y, 'A f@ als .lll I' s May 25, 1937. B, D. BALTHls GAS BURNER AND COMBUSTION CONTROL APPARATUS Filed July 20, 1935 2 Sheets-Sheet 2 l es Patented May 25, 1937 UNITED STATES PATENT OFFICE GAS BURNER AND COMBUSTION CONTROL APPARATUS Application July 20, 1935, Serial No. 32,386

20 Claims.

This invention has to do generally with heating and combustion control apparatus, and relates particularly to improvements in gas burner heating units and conjunctive fuel and air control,

, especially adaptable for industrial units such as boilers, furnaces, retorts and the like.

Among the principal objects of the invention are to provide a burner, or a system of burners, capable of operating at an extremely high degreev 10 of heating and combustion efficiency, and capable of maintaining an intense heating and exceptionally uniform temperature condition throughout the entire area of the zone or surface being directly heated. Generally speaking, such ef- 15 ciency is largely dependent upon maintaining certain exactness in the proportioning and distribution of the primary and secondary air supplied to the burners, and in maintaining a uniformity and stability'of temperature conditions at or in the immediate vicinity of the combustion zones where the fuel leaves the burner nozzles.

The above of course presupposes a proper control of the fuel and general air supply being fed to the burner.

The first of these conditions is met in accordance with the invention by the provision of a new and improved type of burner and burner assembly, so designed as to give an accurate proportioning of both the fuel and primary air, and 30 the secondary air in' relation to the mixture of fuel and primary air. The second mentioned condition is served by providing in conjunction with each burner, or in the burner assembly, heat retaining bodies which serve, despite fluctuation in the combustion rate in the burner, to maintain a closely uniform temperature throughout the entire zone wherein combustion directly is taking place.

With more particular regard to the structural aspects of the invention, one of my primary purposes is to provide a unitary assembly including a burner box containing an assembly of nozzles, and having features of adjustability that enable a box of given size to be installed in combustion 43 chambers or fire boxes whose dimensions may vary within substantial limits, thus obviating the necessity for having to specially design a burner box to fit any particular installation. Another object of the invention is to provide an improved type of burner and burner assembly involving the use of ceramic blocks or fire bricks as heat retaining media whereby the heating and com bustion efficiency, as well as the distribution and maintenance of even temperature conditions, are materially improved. Other objects of the invention pertain to an improved control system for automatically regulating the air supply, and in addition, if desired, the flow of gas to the burners.

All the above mentioned and additional objects and features of the invention will be more fully 5 understood from the following detailed description of the invention in one of its typical and preferred forms. Throughout the drawings reference is had to the accompanying description, in which: 10

Fig. 1 is a sectional view taken longitudinally of the fire box portion of a boiler and showing the burner assembly, the section being taken on line I-I of Fig. 2;

Fig. 2 is a transverse section on line 2-2 of Fig. 1;

Fig. 3 is an enlarged sectional view showing one of the burner nozzles in detail;

Fig. 4 is a perspective showing the burner box and nozzle assembly, together with the gas and air supply control apparatus;

Fig. 5 is a fragmentary view showing the air control door operating diaphragm in section;

Fig. 6 is an enlarged sectional view showing the gas control valve; and 25 Fig. '7 is a fragmentary perspective showing the arrangement and mounting of the adjustment plates at the corner of the burner box.

In Figs. 1 and 2 I have shown the burner assembly, generally indicated at I0, placed within 30 the combustion chamber or fire box II of a typical and conventionally illustrated fire tube boiler B. The boiler shell comprises inner and outer walls I2 and I3 forming the steam chamber I4. Wall I2 encloses the combustion chamber I I, the sides of which are formed by the vertical walls I2a of the inner shell. The particular type and design of the boiler are of course in no way limitative on the invention, since the present burner assembly is capable of installation and applicable for use in various forms of boiler and heating units generally wherein the fire boxes or combustion chambers are adapted to accommodate the burner assembly.

As best illustrated in Fig. 4, the burner as- 4 sembly Ill comprises a box structure I5 having side walls I6, Il, I8 and I9, and a floor 20. The box I5, together with the later described burner assembly, constitute a unitary structure adapted to be installed within the combustion chamber of a boiler after the latter has been set in position. This type of burner unit has the advantage of being readily removable and capable of reinstallation in other boilers, or in the same boiler where, asin oil field practice, the boiler is being moved chamber.

y'g'from place to place and used at different wells or i1: locations.

The size of the burner box i for any particularclnstallationfwill be selected roughly to cor- 5 respond with the cross sectional dimensions of the lower part of the combustion chamber ll. However, clue to the fact that the dimensions of the combustion chamber in different boilers may vary considerably, it is impractical to attempt y lo to build th'e vburner lboxes in all the various rlimensions that would correspond closely to the sizes of the combustion chambers in possible installations. In accordance with the invention, I have provided means whereby a burner box of l5 given size may be made capable of a substantial degree of dimensional adjustability, rendering it adaptable for installation in various combustionv chambers of differentsizes. l

vEach of the side walls of the box l5 has a4 horizontally, and preferably outwardly projecting 5 extending through slots 24 inl the adjustment plates. Plates maybe secured to anges 2| at the corners of the box to prevent anup-draft ofv air between the ends of the adjustment plates 22. In installing the burner assembly Within the combustion chamber il, the box l5 is moved in beneath the chamber and then raised to proper height, as shown in Figs. 1 and 2, the box being supported in Araised position by any suitable means, such as blocks 26. If necessary, adjustment plates 22 are shifted laterally to substantially close off any space between the side walls i2a of the combustion chamber and the outer edges of anges 2|, thus preventing an up-draft ,of air around the box andinto the combustion As will readily appear, the range 'of adjustability of 'i plates 22 is sufficient to enable the spaces around the burner box to be closed 0E, even though there may be considerable difference in the corresponding horizontal dimensions of the box and combustion chamber. If desired, fire brick 2l may be laid, as illustrated, on plates 22 to insulate the wall of the combustionv chamber immediately surrounding the assembly of burners. Preferably, the adjustment 0 plates 22 willbe provided at their inner edges with upstanding flanges 28 for the purpose of confining the re brick 21.

Gas supply manifold 42li is placed within and across one end of the burner box l5. and a series 5 of equally spaced nozzle supply branch pipes 30 extend from the manifold substantially across the box. Each of lpipes 3|) supports a row oi burners 3|, the individual burners in each row being equally spaced, and the corresponding burners inthe rows being alined transversely of the box as viewed in Fig. 2. As best illustrated in Fig. 3, each of the burners 3| comprises a nozzle 32 having a Venturi-shaped gas and air mix- 65 ing passage 33 into which the primary air is drawn through openings 34 by virtue of the velocity of the gas stream being discharged upwardly through bore 35 of the nozzle supporting nipple 36 threaded at 3l within the upset portion 70 38 of the pipe 30. Bore 32a within the bottom of the nozzlebody below the air openings 34 has a sliding fit with nipple 36 so as to enable -the nozzle to be.' slipped over the nipple and Irested on the nipple flange 38a. Gas nozzle tip 36h 75 having a calibrated bore 36e is threaded into the flaring passage 33 aosaesr upper end of bore 35, the nozzle projecting upward sulciently far with relationto the restricted throat 33a of the gas and air mixing passage, to produce the proper aspirating effect in drawing in primary air through openings 34. The fuel and air mixture nozzle 32 `and the upwardly are sufficientlyk long that the gas and primary air during their ilow through the passage will .become intimately and thoroughly mixed to form a combustible mixture of the desired proportions.

A fire brick vlill is supported on each nozzle 32 within the primary air and fuel mixture outlet as defined by rim di, the sides of this brick being spaced from rim 6| so as to provide an elongated vftirely around the brick. The latter may be conveniently supported within the nozzle on lugs 43 cast integrally with the body of the nozzle, and having inwardly Aprojecting portions 43a serving to maintain a minimum clearance between the.

brick and the rirn ill of the nozzle. The fuel .n

combustion thus occurs at the narrow space surrounding the re brick and at the outer surfaces of the latter so that at all times the brick is heated to substantially. the combustion temperature.

It may be mentioned at this point that by reason of the capacity of the re brick for retaining heat, the brick serves to maintain a relatively stable temperature condition at the point of gas combustion'regardless of fluctuations in the rate of flow or 'proportions of the combustible mixture And,'as previously observed, by reason of the maintenance of a relatively uniform high temperature at the point of combustion, a stable temperature condition is established which results in maximum heating and combustion eiliciency. Y

Each of the nozzles 32 also has a series of angular lugs 44 formed on the outside of the side edges of the rim portion 4|, these lugs serving to support rows vof flrebricks a, see Fig. 1, placed between adjacent rows of the `nozzles 3|, and serving the same general purpose as bricks 4U. Lugs ill also maintain bricks 40a in spaced relation to the outer surfaces of the nozzles so as to allow an up-draft of secondary air through the spaces at 45. As shown in Fig. 2, secondary air is-supplied at the ends of the nozzles 3| through spaces 46. The individual burner assembly in each row, as viewed in Fig. 4, may be maintained in proper position and'alinement by bars 'l secured to'one end of each burner.

In the foregoing it has been observed that the mixture of gas and primary air flows upwardly around the bricks 40 through the clearance spaces 432 within the nozzle outlets. The primary air in the initial combustion mixture formed within the burner nozzles is supplemented by secondary air rising through spaces 45 and 46 immediately surrounding spaces 42 within the nozzles, so that a direct and intimate admixture of secondary air with the rst formed mixture, is formed at the point of combustion. As in the case of fire bricks 4|) contained directly within the nozzles, bricks 40a are directly surrounded .by the combustion flame so that all the bricks are ybox is controlled by a pair of pivotally movable Adoors d8 mounted on a shaft 49 journaledv in the ends oi a box structure 50 projecting from side wall I1 of the burner box I5. The air supplied .doors as the gas flow decreases.

to the burner box is automatically regulated in accordance with the rate of gas flow to the burners by means of an apparatus,generally indicated at 5I, installed in the gas supply line 52 connecting through the wall I6 of the burnerbox with the manifold 29. The air control apparatus 5I comprises, generally speaking, a gas pressure respensive means operatively connected with the air control door shaft 49 so as to progressively open the doors 48 to admit more air as the gas flow to the burners increases, and to close the I have illustrated a typical form of pressure responsive device comprising a body 53 having sections 53a and 53h, between which is clamped a diaphragm 54, the underside of which is subjected to the gas pressure in line 52 by way of a nipple connection 55. The diaphragm 54 operates a rod 56 yieldably maintained in engagement with the diaphragm by means of coil spring 51. The upper end of rod 56 is pivotally ccnnected at 56a with lever 58 mounted at 59 on fulcrum 60, and lever 58 in turn is connected via links 6I and 62 with shaft 49, the outer end of link 62 being secured to the shaft by clamp 63.

The gas supply to the burner assembly may be controlled by a valve 64, which may be of a manually operated type, or an automatically controlled valve operated in response to variations in the boiler steam pressure by way of a pressure connection 65. Increased flow of gas to the burners results in an increase in the pressure applied to the underside of diaphragm 54, causing the latter to raise rod 56, and through the linkage 58, 6I and 62, to rotate shaft 49 and open the doors 48 to admit more air. Conversely, a decrease in the rate of gas supply to the burners results in a reduction of the gas pressure against diaphragm 54 and rotation of shaft 49 to move doors 48 toward closed position, decreasing the burner air supply.

The fuel and air control system also embodies means for automatically controlling the gas flow to the burners in accordance with changes in gas pressure applied to diaphragm 54. A gas control valve 66 installed in line 52 beyond the diaphragm device 53 in the direction of gas flow, preferably consists of a simple butterfly valve 61 carried on shaft 68 extending through packing gland 69 in the body portion 1|). The valve is operated from the air door shaft 49 by way of lever 1I clamped to the end of lever 62, link 12, and lever 13 secured by clamp 14 to the valve shaft 68. As the gas flow through pipe 52 to the burners increases and shaft 49 is rotated due to increased pressure against the underside of diaphragm 54, as previously explained, the valve 61 is progressively opened to permit increased supply of gas to the burners. As the gas flow to the burners is throttled by valve 64 and the pressure against diaphragm 54 is decreased, valve 61 is moved toward closed position to throttle the burner gas supply.

It will be understood that the drawings are to be regarded merely as typical and illustrative of the combination comprising a pair of horizontally spaced upwardly discharging burner nozzles, lugs projecting from the inside and outside of the Walls of said nozzles, a fire brick supported on the lugs within each nozzle, and an intervening fire brick supported on the outside projecting lugs of the two nozzles.

2. In combination, a pair of horizontally spaced burner nozzles having upwardly opening mouths, a pair of refractory heatY retaining bodies. one received and spaced within the mouthof each nozzle and forming gas emission slots in said nozzle mouths adjacent the side faces of the corresponding bodies, and an intervening refractory heat retaining body spaced between said first mentioned refractory bodies, there being upwardly extending airspaces between opposite sides of said intervening refractory body and said nozzles. 3. In combination, a pair of horizontally spaced fuel nozzles having flared rectangular upwardly opening mouths, a pair of fire bricks received within said rectangular mouths, said bricks being supported with their side surfaces in substantially vertical planes, there being narrow upwardly extending gas emission slots between the rims at the upper ends of the nozzles and the lower portions of said bricks, and' an intervening fire brick supported between and on the same level with and parallel to said rst mentioned lire bricks, and therev being upwardly extending air spaces between opposite sides of said intervening brick and said nozzles, opposing side surfaces of said bricks defining two vertically extending combustion spaces for the flame issuing from between the rims of the nozzles and the nozzle received bricks.

4. A gas burner assembly embodying the combination of: a heat retaining ceramic oor comprised of a plurality of ceramic blocks having substantially flat vertical faces horizontally spaced apart; and a plurality of burners beneath said blocks, marginal portions cf the discharge openings of said burners cooperating with certain of said blocks to form gas emission slots in the spaces separating the successive blocks.

5. A gas burner assembly embodying the combination of: a heat retaining ceramic floor comprised of a plurality of ceramic blocks having r substantially flat vertical faces horizontally spaced apart; a plurality of burners beneath said blocks, marginal portions of the discharge openings of said burners cooperating with certain ofsaid blocks to form gas emission slots in the spaces separating the successive blocks; and cooperative means for supporting said burners and said blocks to provide a unitary assembly.

6. A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractory blocks having substantially flat vertical faces horizontally spaced apart; and burners positioned beneath the alternate blocks in said row, marginal portions of the discharge openings of said burnersA cooperating with the said alternate blocks to form gas emission slots in the spaces between the successive blocks.

7. A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractory blocks having substantially fiat vertical faces horizontally spaced apart, burners positioned beneath the alternate blocks in said row, marginal portions of the discharge openings of said burners cooperating with the said alternate blocks to form gas emission slots in the spaces between the successive blocks; and v 8. A gas burner assembly embodying the com-'- bination of a heat retaining floor comprised of a row of refractory blocks having substantially flat vertical faces horizontally spaced apart; and burners positioned beneath the.` alternate blocks in said row, said burners having flared discharge openings shaped to conform substantially with and to surround thev said alternate blocks, thereby forming gas emission slots in the spaces between the successive blocks in said row.

9. A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractory blocks having substantially flat" vertical faces horizontally spaced apart; burners positioned beneath thealternate blocks in said row, said burners having flared discharge openings shaped to conform substantially with and to surround the said alternate blocks, thereby forming gas emission slots in the spaces between the successive blocks of 'said row; and iny ternal and external projections on the discharge openings of said burners for supporting all of said blocks.

10. A gas burner assembly embodying the combination of a heat retaining ceramic floor cornprised of a plurality of ceramic blocks having substantially at vertical surfaces; a plurality of burners beneath said blocks, marginal portions of the discharge openings of said burners cooperating with certain of said blocks to form gas emission slots in the spaces separating` the successive blocks; and means at the discharge openings of said burners supporting said blocks.

11; A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractory blocks having substantially flat vertical faces horizontally spaced apart; burners positioned beneath the alternate blocks in said row, marginal portions of the discharge openings of said burners cooperating with the said alternate blocks to form gas emission slots in the spaces between the successive blocks; and means at the discharge openings of said burners for supporting said blocks.

12. A gas burner assembly embodying the com- I bination of a heat retaining ceramic floor comprised of a plurality of ceramic blocks having substantially flat vertical surfaces; a plurality of burners beneath said blocks, marginal portions of the discharge openings of said burners cooperating with certain of said blocks to form gas emission slots in the spaces separating the successive blocks; means at the discharge openings of said burners supporting said blocks; and means supporting said burners. y

13. A gas burner assembly embodying the combination of: a heat retaining floor comprised of a row of refractory blocks having substantially flat vertical faces horizontally spaced apart; burners positioned beneath the alternate blocks in said row, marginal portions of the discharge openings of said burners cooperating with the said -alternate blocks to form gas emission slots in the spaces between the successive blocks; means at the discharge openings of said burners for supporting said blocks; and means for supporting said burners.

14. A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractory blocks having substantially flat vertical faces horizontally spaced apart; burners positioned beneath the alternate blocks in said row, said burners having flared discharge openings shaped to conform substantially with and to surround said alternate blocks. thereby forming substantiallyA straight flame slots adjacent opposite faces of each of said' alternate blocks; internal and external projections on the discharge openings of said burners supporting all of said blocks; a gas manifold; and connection meanson said manifold supporting said burners thereby providing a lunitary portable assembly.

15. A gas burner assembly embodying the combination of a heat retaining ceramic floor comprised of a plurality of ceramic blocks each having side faces horizontally spaced from the corresponding faces of adjacent blocks, the adjacent faces oi.' successive blocks defining upwardly extending spaces therebetween; and a plurality of burners beneath said blocks and having discharge openingsv terminating substantial distances below the upper ends ofsaid blocks, marginal portions of said discharge openings cooperating with certainl of said blocks to form gas emission slots in the spaces between said blocks.

16. A gas burner assembly embodying the combination of a heat retaining ceramic floor comprised of a plurality of ceramic blocks each having side faces horizontally spaced from the corresponding faces of adjacent blocks, the adjacent faces of successive blocks defining upwardly extending spaces therebetween; a plurality of burners beneath said blocks andv having discharge openings terminating substantial distances below the upper ends of said blocks, marginal portions of said discharge openings cooperatingl with -certain of said blocks to form gas emission slots in the spaces between said blocks and cooperative means for supporting said burners and said blocks to provide a unitary assembly.

17. A gas burner assembly embodying the combination of: a heat retaining ceramic oor comprised of a plurality of ceramic blocks each having side faces horizontally spaced from the corresponding faces of adjacent blocks, the adjacent faces of successive blocks defining upwardly extending spaces therebetween; a plurality of burners beneath said blocks and having dis' ymeans at the discharge openings of said burn-I ers for supporting said blocks; and means supporting said burners.

18. A gas burner assembly embodying the combination of: a heat retaining door comprised of a row of refractory blocks horizontally spaced apart to form vertically extending spaces defined by adjacent outside faces on the successive blocks in said row? and a plurality of burners beneath said blocks, marginal portions of the discharge openings of said burners cooperating with certain of said blocks to form gas emission slots in the vertically extending spaces.

19. A gas burner assembly embodying the combination of a heat retaining floor comprised of a row of refractoryblocks horizontally spaced apart to form vertically extending spaces dened by adjacent outside faces on the successive blocks in said row; a plurality of burners beneath said blocks, marginal portions of the disative means for supporting said burners and said blocks to provide a unitary assembly.

20. A gas burner assembly embodying the combination of: a heat retaining floor comprised of a row of refractory blocks horizontally spaced apart to form vertically extending spaces dened by adjacent outside faces on the successive blocks in said row; a plurality of burners beneath said blocks, marginal portions of the discharge openings of said burners cooperating with certain of said blocks to form gas emission slots in the vertically extending spaces, means at the discharge openings of said burners for supporting said blocks; burners.

BEN DOUGLASS BALTHIS.

and means supporting said l 

